Washington County Sheriff's Office cold-case investigator Mike O'Connell on Friday detailed some of the developments, including DNA evidence, that ultimately led authorities to identifying and capturing a suspect in a decades-old Aloha homicide.

O'Connell during a press conference and subsequent interview credited the thorough work of the first detective who took the case after 17-year-old Lori Billingsley was found raped, beaten, stabbed and strangled along an Aloha road in 1982. Recorded interviews following the brutal killing and critical advancements in the state crime lab's capability to analyze DNA were among the things that helped close the case, he said.

Three state police troopers arrested Kenneth Lee Hicks in Billingsley's death after conducting a traffic stop as the 49-year-old left his St. Helens home for work early Wednesday morning, O'Connell said. While authorities took Hicks into custody, his demeanor was flat, the detective described.

Last year, authorities learned that DNA collected from a rape kit performed on Billingsley after her death matched Hicks' profile, O'Connell said. He is charged with two counts of aggravated murder and is being held in the Washington County Jail without bail.

Court records accuse Hicks of raping Billingsley, then killing her to cover up the sexual assault.

Investigators say they wish the arrest could have been made before Billingsley's parents died. Solving the homicide and giving the family an arrest, O'Connell said, feels good. But the investigation on the case will continue until it's resolved.

"It's very rewarding," he said. "But I have no illusions. The work has just begun."

The county does not have a team of detectives assigned solely to cold cases. But O'Connell, who retired from the sheriff's office after spending more than 20 years in the agency's investigations division, returned in December 2010 to work unsolved homicides on part-time basis as a temporary employee.

The Billingsley case was one of the first O'Connell looked at. He pored over the file. Sheriff's Detective Murray Rau served as a partner in the investigation.

Cold cases, O'Connell said, are cold for a reason. The cases take more work and persistence than he could have imagined.

"They are really, really difficult," he said.

It's challenging to interview people about things that happened 30 years ago, he said. A witness, who was 12 at the time of Billingsley's killing, doesn't remember anything now.

Deputies found Billingsley's body on Oct. 10, 1982 in a ditch along Southwest Miller Hill Road in Aloha, after a couple taking a walk discovered the girl. She was last seen the night before, as she left the Aloha apartment she shared with her mother and younger sister.

When authorities first found Billingsley, police didn't know who she was. Investigators initially identified her from a clothing description her mother provided police when she reported her missing, the detectives said. They later confirmed the identification with her fingerprints at an autopsy and those found in her room.

Hicks was interviewed twice after the killing, O'Connell said. Authorities identified him as a potential suspect, but, at the time, they did not have enough evidence to charge him.

In 1991, the sheriff's office submitted evidence related to the case to the state police crime lab. But DNA technology was limited at the time, and investigators could not identify a DNA profile.

After reopening the case, the sheriff's office in 2010 again sent a small piece of evidence to the crime lab, which was able to identify a DNA profile. When the profile did not match anyone in a law enforcement database, investigators again turned to Hicks.

Last spring, O'Connell said he prepared a search warrant to obtain Hicks' DNA. Authorities had not contacted Hicks since the 1980s.

Detectives had a brief conversation with Hicks, who had been married for more than 20 years. He appeared surprised to see the investigators.

In statements to police, Hicks "gave very different versions of the event, and they both couldn't be true," O'Connell said.

Hicks, O'Connell said, has provided no explanation for how his DNA could have been found on Billingsley. The detectives didn't go into further detail about Hicks' statements.

After seizing swabs of his DNA, investigators submitted it to the crime lab. A few weeks later, O'Connell said, they learned that it matched DNA from the rape kit.

"I was ready to just go out and arrest him," O'Connell said.

Investigators continued collecting evidence.

"But the truth is that no other evidence would hold a candle to the DNA," he said.